1. Field of the Invention
This invention relates to coaxial cable connectors of the type used in CATV systems.
2. Description of Related Art
Coaxial cable connectors which are threaded onto complimentary interface connectors are commonly used for the purpose of electrically integrating coaxial cables with various electronic devices such as televisions, citizens band radios, FM radios, and amateur radio systems. A standard for such coaxial cables in the "F"-type connector. F-type connectors have attained near universal application in video and cable T.V. systems.
A primary function of F-type coaxial cable connectors is to ensure good engagement between the shield element of the coaxial cable and the conductive connector body for the purpose of electrical signal transmission to a connector interface. A problem with prior art coaxial connectors is that moisture can infiltrate into the connector body, between the connector body and the coaxial cable or between the connector body and the interface connector. This is especially true in the case of cable T.V. systems which frequently require outdoor connections.
Moisture infiltration between the connector body and the coaxial cable is believed to be the result, at least partly, of the manner in which the connectors are crimped to the cable. Conventional crimping tools do not apply a uniform compression force on the outer surface of the connector body at the point of crimping. Generally, such tools are hexagonal and leave several uncompressed or partially compressed zones between the jacket seal and the coaxial cable jacket. These zones are possible avenues for moisture infiltration. Also, the connectors themselves are not designed to take into account the curvature or variations in diameter of the cable at the point of crimping. Infiltrated moisture may eventually contact the braided shield and degrade the signal transmission performance of the connector.
Moisture infiltration which occurs between the interface connector and the connector body, on the other hand, generally results from an improper o-ring seal in the conventional connector. Again, such moisture infiltration may degrade the signal transmission performance of the connector. While o-ring seals are generally satisfactory, it is possible for the o-ring to become improperly seated or unevenly compressed when making the connection, resulting in possible shearing of the ring and RF leakage, as well as moisture infiltration past the ring.
A final problem in regard to F-type coaxial cable connectors is that a different connector structure is required for different types of commonly used coaxial cables even if the sizes of the cables are the same. In order to accommodate the different cable styles, adaptors or additional parts are often required, adding to cost and to the number of gaps through which moisture can penetrate.